Insulator.



1. n. HARms.

lusuuron.

kFPLIcATloN FILED luLlv 1|.

Patented Apr. 29, 1919.`

UNITED STATES PATENT JOHN n. :annata or cHAnTIEns TOWNSHIP, ALLEGHENY COUNTY, PENNsYLvANrA.

INSULATOR.

Specification of Letters Patent.

Patented Apr. 29, 1919.

Application led .Tuly 11, 1917. Serial No. 179,841.

have invented ordiscovered new and useful Im rovements inl Insulators, of which the v i fol owing is aspecificati'on.

lMyinvention consists in certain new and useful improvements in two part insulators or (split knobs used for electrical wiring.

' In the use of two part insulators for securin wires in place, especially where the insu ators must be installed in locations difficult of access, considera-ble trouble is eX- perienced in keeping the insulator or its parts in proper' position to receive and securethewire in pro er alinement. Thus the wire groove inthe ase or cap and base of the insulator must be turned into the proper position tol receivefand hold the stretched wire, and this `adjustment is very diiii'cult where the workman has a cramped or awkward lspace to work in or where the light is poni-,as 1s frequently the case where wiring done under a floor which must be as little as possible.

IIovert".'orne these diiiiculties by mounting the insulator 'onthe nail or other attaching member in such a manner that it will not rotate thereon, but when the nail is once started intolthe joist or other support in the prpermannenjthe wire may' be inserted and i thenailldrivenhome witlthe positive asthatlthe wiregroove or grooves will tlieproper position inrelation to the ofthe wire. .Where theregifs'ttatioiiof t e cap with the base is not important, thefbae' alone may be non-rotativelyv Ion the inail, but' Where the groovein'thecap must register with the fgroove in the base, both the cap and base are so 'mounted onthe nail that they cannot rotate thereon ,but their. erwies v1.11 always niintaiiithe desi'md relative positions.l

I also provide new and improved means ure 1` is a side elevation showing my improved insulator with the attaching element started into the joist or other support `and the base and cap separated for the introduction of the wire. Fig. 2 is a longitudinal section of the cap and base with theatta'ching element driven home into the joist so as to secure the insulator in place with the wire clamped between the cap and base, the wire being omitted for the sake of clearness. Figs. 3, 4: and 5 are cross sec-tions showing various forms of attaching members and holes through which they pass,A illustrative of various embodiments of my invention, such sections being taken along the dotted line III-III in Fig. 2. Fig. 6 is a side elevation of an insulator showing means for holding .the cap and base in proper assemblage duringshipping or before installation on the job. Fig. 7 is a similar viewl showing a modification, and Fig. 8 is a butt end View ofv the latter.

The following is a detailed description of my invention as illustrated in the drawings.

Al represents the base of' a twozpart 1nsulator: B its cap, and C the nail or other element by means of which the insulator is mounted in place. D represents a joistor other support to which the insulator is to be firmly attached with the electrical wire, not shown, clamped between its cap and base. 1 represents lthe wire groove which extends transversel of the outer end of the base at one side o its axis, and in the drawings 'I have shown the cap provided with a similar groove 2 which must register with'the groove 1 to properly eng e the wire. I have shown the' outer ends o both -the baseandy capcountersunk in the usual 'manner but this feature forms 'no partof my presentinven` tion. Both'the'lbase and cap are provided with axial holes or bores for receiving the attaching member or nail. Thus-in Fig. 3, I have shown the axial hole 3 Ain the base A of,rect-angu'lar cross section andthe nail' C i of pi'per cross sectional shape to fit in the assure the prevention of the rotation of the base on the nail.

Where the cap as shown in Figs. 1, 2, 6 and 7, is provided with a transverse wire groove, its axial hole t should be also of proper cross sectional contour to fit the nailv or other attaching element in such a man ner as to be held against rotating thereon.

To enable the parts of the insulator to be assembled on the nail or other attaching element at the factory, so as to be delivered at the job, ready to be installed, in' proper relationship, and thus avoiding the loss of time otherwise required to sort out the bases and caps, I mount on the nail C a small brad 5 which is seated in asmall hole 6 bored transversely through the outer end of said nail, as shown in Fig. 6. Or I'may provide two parallel or opposed face surfaces of the nail with transverse slots 7 and slip over the nail a spring wire loop or clip 8. These fasteners 5 or 8 may be removed when the insulator is about to be installed. In Fig. 2 I show the nail flattened out outside the base A of the insulator, as at 9. This forms a more secure method of holding the parts together but is more expensive to use.

It is evident from the foregoing that my invention is attended by numerous a vantages. Thus it greatly expedites the work of putting up electrical wires, because but very little care is required to properly position and set the insulators, and the work can easily be done in a very cramped space and with poor light, without impairing the accuracy and quality of the job.` Since the insulators are properly placed and their grooves alined, slacking of the wire is avoided, and a firm grip is obtained on the wires between the caps and bases of the insulators. The wire grooves are kept in proper position and' automatically grip the wlre with an even uniform engagement which prevents injury or chafing of the insulation and is not susceptible to accidental loosening. These advantages are gained without increasing the oost of the insulators. The use of the fastening element on the inner end of the nail or other attaching element Venables the cap and base to be assembled in proper relation at the factory, thus saving much time on the job.

What I desire to claim is 1. A wire supporting knob of the character described, comprising clamping sections of suitable insulating material having parallel registering wire receiving grooves and axial rectangular apertures, and a rectangular nail which passes through the apertures n said sections.

2. A wiring knob of the character described, comprising clamping sections of suitable insulating material having parallel registering wirereceiving grooves, and axial apertures which are other than round and a nail which passes through said apertures, which is of the same outline in cross section as said apertures.

3. A wiring knob o-f the character described, comprising clamping sections, of suitable insulating material, having axial rectangular apertures adapted to receive a nail of a cross sectional shape corresponding to the shape of said apertures.

4. A wiring knob of the character da scribed, comprising clamping sections, of suitable insulating material having axial apertures which are otherthan round in cross section, and which are adapted to receive a nail of corresponding shape in cross section.

5. The combination with a two part insulaxtor comprising a base and.v a' cap, said base being provided with a transverse wire groove, both of said elements being provided with an axial hole and the axial hole in said base being of non-circular cross section, and. a member, adapted to attach"'said insulator to a support, extending through said axial holes and fitting the hole in said base, whereby said base is held against rotation in relation to said member, for the purpose set forth. l y

v6. The combination of a two part insulator comprising a base and -a cap, both of. said elements being provided with an axial hole of non-circular cross section, and a member, adapted to attach said insulator to a support, extending through said axial holes and fitting the same, whereby the parts of said insulator are held against rotation in relation to said member, for` the purpose set forth. f

Signed at Pittsburgh, Penna., this 9th day of July, 1917.

JOHN R. HARRIS.

Copies of this patent may be obtained for've cents each, by addressing the Commissioner of Iatentl, Washington, D. 0. 

